1. Definition

Screening is a process of identifying apparently healthy people who may be at increased risk of a disease or condition. They can then be offered information, further tests and appropriate treatment to reduce their risk and/or any complications arising from the disease or condition.

2. Another way to look at screening

The following animations explain screening by comparing the screening process to using a sieve. They are shown here by courtesy of the English NHS Newborn Hearing Screening Programme. Click on each animation in turn to play them. Make sure you have sound on if possible as they have voiceovers.

The basics of screening

Words associated with screening

Prevalence:

Sensitivity and specificity:

False positives and false negatives:

3. The screening process illustrated

This graphic provides a visual illustration of the screening process, showing again how screening can be compared to using a sieve to find people at high risk of having a certain condition. Click to enlarge it.

4. Limitations of screening

Screening has important ethical differences from clinical practice as the health service is targeting apparently healthy people, offering to help individuals to make better informed choices about their health. However, there are risks involved and it is important that people have realistic expectations of what a screening programme can deliver.

Whilst screening has the potential to save lives or improve quality of life through early diagnosis of serious conditions, it is not a fool-proof process. Screening can reduce the risk of developing a condition or its complications but it cannot offer a guarantee of protection. In any screening programme, there is a minimum of false positive results (wrongly reported as having the condition) and false negative results (wrongly reported as not having the condition). The UK NSC is increasingly presenting screening as risk reduction to emphasise this point.

5. NHS Screening: Doing More Good than Harm video

A 3½ minute video, narrated by Martyn Lewis, giving an excellent overview of screening using examples from the newborn blood spot and newborn hearing programmes.

6. Online tutorial covering all the basics of screening

The new Health Knowledge module on screening is an excellent, really easy to understand, ‘interactive learning module’ covering all the basics of screening. It has been developed by Dr Angela Raffle who has many many years of experience in screening. It is split into chapters so that it is easy to work through bit by bit.